Investments (Tables)

9 Months Ended

Sep. 30, 2012

Investments, Debt and Equity Securities [Abstract]

Summary of short-term investments

A summary of the Company’s short-term investments at September 30, 2012 and December 31, 2011 is as follows (in thousands):

	As of September 30, 2012									As of December 31, 2011
	Cost		Gross Gains		Gross Losses			Fair Value		Cost		Gross Gains		Gross Losses			Fair Value
Municipal Securities	$	10,395	$	—	$	(113	)	$	10,282	$	11,413	$	—	$	(115	)	$	11,298
Corporate Debt Securities	30,113		—		(248		)	29,865		33,723		—		(327		)	33,396
Commercial Paper	13,959		2		—			13,961		4,991		—		(2		)	4,989
U.S. Agencies	—		—		—			—		4,528		—		(17		)	4,511
Certificates of Deposits	23,023		—		—			23,023		23,071		—		—			23,071
Total	$	77,490	$	2	$	(361	)	$	77,131	$	77,726	$	—	$	(461	)	$	77,265

Schedule of financial assets measured at fair value on a recurring basis

Financial assets measured at fair value on a recurring basis as of September 30, 2012 were as follows (in thousands):

	Quoted Prices in Active Markets for Identical Assets Level 1		Significant Other Observable Inputs Level 2		Significant Unobservable Inputs Level 3		Total
Money Market Funds	$	20,143	$	—	$	—	$	20,143
Certificates of Deposits	23,023		—		—		23,023
Corporate Debt Securities	—		29,865		—		29,865
Commercial Paper	—		13,961		—		13,961
Municipal Securities	—		10,282		—		10,282
U.S. Agencies	—		—		—		—
Auction rate notes	—		—		6,884		6,884
Total	$	43,166	$	54,108	$	6,884	$	104,158

Financial assets measured at fair value on a recurring basis as of December 31, 2011 were as follows (in thousands):

	Quoted Prices in Active Markets for Identical Assets Level 1		Significant Other Observable Inputs Level 2		Significant Unobservable Inputs Level 3		Total
Money Market Funds	$	55,912	$	—	$	—	$	55,912
Certificates of Deposits	23,071		—		—		23,071
Corporate Debt Securities	—		33,396		—		33,396
Commercial Paper	—		4,989		—		4,989
Municipal Securities	—		11,298		—		11,298
U.S. Agencies	—		4,511		—		4,511
Auction rate notes	—		—		6,857		6,857
Total	$	78,983	$	54,194	$	6,857	$	140,034

Schedule of changes in Level 3 securities

For the nine months ended September 30, 2012, the changes in the Company’s Level 3 securities (consisting of auction rate notes) were as follows (in thousands):

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
Beginning balance, December 31, 2011	$	6,857
Transfers in and/or out of Level 3	—
Total gains, before tax	127
Settlements	(100		)
Ending balance, September 30, 2012	$	6,884